Abstracts (complete list) - Wissenschaft Online

Martin Kolev, Marieta Ruseva, Steffen Thiel, Frederik Hansen, Jens Jensenius
On the role of MBL in a murine model of oral infection with
Salmonella typhimurium
Salmonella enterica is a gram-negative intracellular microorganism, which grows in the
mononuclear phagocytic system of the host and causes disease. The complex
interaction between the both host and the bacterium is still unknown. Multiple humoral
and cellular effector mechanisms, implicated in host resistance to Salmonella infections
have been described.•
Complement plays a major role in host defense against bacteria and fungi. •
MBL (mannan binding lectin)-a plasma protein belonging to a family of proteins known
as collectins. It interacts with a wide array of microorganisms, including Salmonella spp. •
Mice and calf models have been used to study the mechanism of Salmonella infection in
vivo. •
The model we used relies on pretreating mice with Streptomycin, which kills the normal
gut flora and allows for subsequent infection with Salmonella.•
We infected them with Salmonella enterica serovar Typhimurium SL1344 - a naturally
occurring strain that is streptomycin resistant.•
We followed the course of Salmonella infection for 3 days in wild-type (WT) female
C57BL/6 mice and compared disease severity with female MBL double knock-out (DKO)
mice (both MBL-A and MBL-C deleted). We observed about 100 fold increased bacterial
loads of the cecum in MBL DKO compared to wild-type animals. These results were also
confirmed by H&E staining of ceca cryosections. There was also an about 10-fold
increase in bacterial loads in fecal pellets of MBL DKO mice, when compared with WT.
However, no difference in liver loads between WT and DKO was observed. The latter
suggests that the infection after 3 or 4 days is systemic. The greater severity in DKO
was also reflected by rapid weight loss. •
The results suggest an important role of MBL in the immune response to systemic
Salmonella infection.